The present invention generally relates to air-bag-door-equipped vehicle interior trim articles and methods for fabricating the articles.
Among air-bag-door-equipped vehicle interior trim articles that have been conventionally known, Japanese Unexamined Patent Publication No. 7-291078 discloses one in which a reinforcing plate section is fixed to the bottom side of a panel main body by performing caulking utilizing heat, and a frame body for accommodating an air bag device is fastened to the plate section. In the vehicle interior trim article of this type, the frame body is provided with a flange fixture part, and the fixture part and plate section are fastened to each other. The vehicle interior trim article is further provided with: a thin rupturable portion located in the panel main body so as to face the fixture part of the frame body; and a slit opening located in the plate section. In such an arrangement, the rupturable portion is immediately ruptured upon activation of the air bag device.
Japanese Unexamined Patent Publication No. 2000-71924 discloses another conventional air-bag-door-equipped vehicle interior trim article that is provided with a support assembly on the bottom side of a panel main body having a door section. The support assembly includes: an outer rim having an opening; a plate section that is located within the opening, and is vibration welded to the bottom side of the door section; a support wall to which an air bag device is fastened; and a hinge section through which the outer rim is connected to the plate section. The support assembly is provided with gaps each having a predetermined width and each formed between the outer rim and an end of the plate section except a portion of the support assembly at which the hinge section is provided. The vehicle interior trim article is further provided at its panel main body with a thin rupturable portion extending along the gaps. In such an arrangement, upon activation of the air bag device, the rupturable portion is ruptured to open the door section.
In fabricating the vehicle interior trim article, the outer rim, plate section, support wall and hinge section are integrally formed by injection molding, for example, and then the outer rim is welded to the panel main body at a portion thereof located around the door section while the plate section is welded to the bottom face of the door section. In this manner, it becomes possible to obtain the air-bag-door-equipped vehicle interior trim article including the support assembly provided on the bottom side of the panel main body.
On the other hand, U.S. Pat. No. 6,089,642 discloses still another conventional vehicle interior trim article including flexible hinge members provided on the bottom side of a pair of upper and lower door sections that opens toward the rear of a vehicle. These flexible hinge members are formed separately and each include a plate section, a hinge section and a leg section. Each of the leg sections is fixed to a support section extending away from a panel main body, and each of the plate sections is fixed to the corresponding door section. Furthermore, one end of one of the plate sections located opposite to the other end thereof at the hinge section protrudes so as to form a stepped extreme end at the bottom side of the panel, and this extreme end extends beyond a rupturable portion to overlap with the extreme end of the other plate section at the bottom side of the panel.
However, the above-described conventional vehicle interior trim articles present various problems as explained below.
The vehicle interior trim article disclosed in Japanese Unexamined Patent Publication No. 7-291078 additionally requires fasteners such as bolts and nuts in order to fix the frame body to the panel main body, which increases the number of components, the number of steps for assembling the article, and the cost of the components.
The vehicle interior trim article disclosed in Japanese Unexamined Patent Publication No. 2000-71924 is formed to improve its fabrication efficiency by integrally forming the plate section and a frame body including the outer rim, for example, and to easily open the plate section by forming a gap between the extreme end of the plate section and the outer rim. In such an arrangement, however, the plate section cannot sufficiently reinforce the panel main body, and thus the panel main body might be broken by a pressure applied thereon by a vehicle occupant, for example.
Further, in the vehicle interior trim article disclosed in Japanese Unexamined Patent Publication No. 2000-71924, the gap formed between the extreme end of the plate section and the outer rim is similar in width to the gaps formed between the lateral ends of the plate section and the outer rim. However, in order to secure these gaps, the area of the plate section is made small, thus making it difficult to increase the overall strength of the door section by the support assembly. In addition, if any one of the gaps is increased in width, the pressing force of an air bag is concentrated on this gap to prevent the rupturable portion formed at the door section from rupturing. As a result, a part of the panel main body located around the rupturable portion is cracked, and the cracked part is scattered.
To cope with these problems, the width of each of the gaps may be minimized. In such a case, however, the frame body and the plate section might be connected to each other due to burrs during the molding of the support assembly. Therefore, the support assembly cannot be fabricated efficiently unless each of the gaps is kept wide to a certain extent.
On the other hand, in the vehicle interior trim article disclosed in the U.S. Pat. No. 6,089,642, since the extreme end of one of the plate sections is formed to extend beyond the rupturable portion to overlap with the extreme end of the other plate section at the bottom side of the panel, a gap formed between both the plate sections can be closed. However, in order to mold both the plate sections so that the gap therebetween can be closed, the flexible hinge members need to be separately molded, and then they have to be separately attached to the panel main body. Consequently, this conventional arrangement increases not only the number of components but also the complexity of the step of assembling the vehicle interior trim article.